(a) Field of the Invention
The present invention relates to a copper-clad laminate for a vehicle light emitting diode (LED) lamp, a printed circuit board including the same, and a manufacturing method thereof.
(b) Description of the Related Art
Recently, use of environmentally-friendly LED lighting devices has increased because of their excellent efficiency and lifespan, and particularly in a vehicle, lamps in which high efficiency LEDs operated with low power have been used as a light source have gained a great deal of attention. In order to ensure front and rear sight and to ensure visibility of the vehicle during daytime driving, a headlamp, a daytime running light lamp, a rear combination lamp, and the like have been used in the vehicle, and for this purpose, high luminance LED lamps may be required.
Since the high luminance LED light source emits about 70 to 80% of inputted energy as heat, when the high luminance LED lamp is applied, the heat generated therefrom should be properly released. When the heat generated from the high luminance LED lamp is not effectively released, since temperature thereof rises, a normal operation of the LEDs may be disturbed, and a failure rate of parts of the high luminance LED lamp may increase, the light efficiency and lifespan thereof may deteriorate. In addition, damage and malfunction of mechanical parts thereof may occur due to thermal stress or thermal expansion. Accordingly, to manufacture an excellent LED head lamp with an excellent heat dissipation characteristic, use of an LED chip with high efficiency and an excellent circuit board with an excellent heat dissipation characteristic may be required.
Further, a flexible printed circuit board (FPCB) that may be three-dimensionally designed as applied to a vehicle exterior LED lamp has been researched as a circuit board. In this case, a flexible copper-clad laminate (FCCL) having the excellent heat dissipation characteristic is required. The FCCL using an insulating layer formed of a polyimide (PI) may be classified into a 2-FCCL and a 3-FCCL depending on presence or absence of an adhesive, wherein the adhesive used in the 3-FCCL is an epoxy or acryl adhesive. However, because of a thickness and low thermal conductivity of an adhesive layer of the 3-FCCL using the adhesive, the 3-FCCL has a less heat dissipation characteristic than the 2-FCCL. In order to improve the heat dissipation characteristic in the conventional FCCL, a heat dissipation filler made of alumina, boron nitride, aluminum nitride, and the like can be added to a PI-based insulating layer. However, since the added heat dissipation filler causes deterioration of mechanical strength of the insulating layer, reducing a thickness of the insulating layer may be necessary as ensuring the mechanical strength thereof.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.